Technical Field
The present invention relates generally to semiconductor devices, and more specifically, to using chemical-mechanical planarization (CMP) and reactive ion etching (RIE) to establish a top contact to active magnetic tunnel junction (MTJ) devices.
Description of the Related Art
A spin torque magnetic random access memory (MRAM) device uses a two terminal spin-torque based memory element. The two terminal spin-torque based memory element includes a pinned layer, a tunnel barrier layer, and a free layer in a magnetic tunnel junction (MTJ) stack. The pinned layer is also called the reference layer. The magnetization of the pinned layer is fixed in a direction such that when current passes through the MTJ stack, the free layer becomes either parallel or anti-parallel to the pinned layer. Resistance of the device depends on the relative orientation of the free layer and the pinned layer.